Electrical heating unit



R. G. KLOEFFLER.

ELECTRICAL HEATING UNIT.

APPLICATION FILED nov. 26, 1920.

1,959 Patanted 51133; 4, 1922 "I'IIIIIIA mum wuulnnum mum1Inan:"ulnar/lulu;

IN l/E Al 70/? E 6.15 ioefi fez" BY m A TTORNEYS PATENT OFFICE.

ROYCE GERALD KLOEFFLER, or MANHATTAN, KANSAS.

ELECTRICAL HEATING UNIT.

Specification (if Letters Patent.

Patented July 4, 1922.

Application filed November 26, 1920; Serial No. 426,473.

To all whom it may concern:

Be it known that I, ROYCE G. KLoEFELER, a citizen of the United States, and a resident of Manhattan, in the county of Riley and State of Kansas, have invented a new and useful Improvement in Electrical Heating Units, of which the following is a full,

clear, and exact description.

My invention relates to improvements in electrlcal heating units, andit consists in the combinations, constructions and arrangements herein described and claimed.

The main disadvantage of the electrical heating units now in use today lies in the difficulty of replacing the resistance coil, or heating coil, when it burns out. The best material known for use in resistance coils has a life in service of from one to three years. At the time of burn-out, the coil must be replaced, or the heating unit discarded.

An object of my invention is to provide a heating unit so constructed as to permit the resistance wire to be readily replaced when burned out. p

A further object of my invention is to provide a heating unit which can be cheaply manufactured, owing to the factthat the major ortion of the device may be stamped from s eet metal.

A further object of my invention is to provide a device which can be readily as-- sembled, without the necessity of using a multiplicity-of screws, bolts, or similar re taining devices. 1

A further object of my invention is to provide a heatingunit, having-novel means for retaining'the insulating members of the unit.

My invention isillustrated in the accom-.

panying drawings, forming part of this application, in which- Figure 1 is a plan view of one embodiment of my invention, certain portions being broken away,

Figure 2 is a transverse section through the device. certain portions being shown in side elevation for the sake of clearness,

Figure-3 is a section along the line 3-3 of Figure 1,

Figure 4 is a plan view of one of the retaining elements,

Figure 5 is a section along the line 5-5 of F igure 4:, and

Figure 6 is a section along the line 66 of Figure 1.

In carrying out my invention, I provide a r ng shaped body portion 1 of sheet metal, whlch has an integral outwardly extending flange 2. Extending inwardly from the body portion are integral spoke-like supporting members 3, whose side edges are turned upwardly to form sockets for insulating strips 4. These strips may be made of any suitable insulating material, such as porcelain, or the like, and are provided with grooves 5 for holding the resistance wires 6, which are connected up, as shown in Fig- .ures 1 and 3, with the three terminals 7, 8

and 9, the latter being insulated from the body portion 1 by an insulating bushing 8', and be ng held in position by means of nuts 9, or in any other suitable manner. The outer endsfof the terminals 7, 8 and 9 constitute plugs for electric connections from v a suitable source of current.

The spoke-like supporting members 3 unite to form a central integral hub-like member 10, which has the form of an inverted cup, and which is provided. with struck up tongues 11, arranged to enter slots 12 in the bottom of a cup-like retaining cap 13,

which has a rim 14 arranged to overlie the upper edges of the insulating strips 4, so as to lock them in position. The opposite ends of the insulating strips 4 are held by means.

of lugs 15 which are the body portion 1.

Arranged to cooperate with the body portion 1 is a cover portion, consisting of an outer ring 16, having a depending flange 17 arranged to overlie the flange 2 of the body portion, so as to accurately center the cover portion. The cover portion is also provided with radially extending integral spoke-like members 18, to the undersides of which are secured sockets 19 for upper insulating members 20, which hold the wires 16 in position, when the parts are assembled. The sockets 19 consist of strips, having downwardly bent ends and sides, these strips being secured to the spoke-like members 18 by spot welding, or in any other suitable manner. The strips 18 are connected by intermediate integral pressed inwardly from strips 21, which are arranged in concentric formation, so as to prevent the dropping of knives, forks, or'spoons upon the heating wires, thereby short circuiting the latter.

Beneath the grid formed by the-spoke-like members 3 is disposed a reflector plate 22.

In assembling the parts, a cup-shaped member 23, having a central threaded portion, which constitutes a nut, is disposed just underneath the upper cover portion. A second nut 24 is. disposed underneath the cup shaped member 10, and a third nut 25 is disposed underneath the reflector 22. A central screw bolt 26 passes through the nuts 23, 24 and 25, thereby securing the parts firmly together.

By unscrewing the nut 25, the reflector plate may be removed for cleaning. By unscrewing the nuts 25 and 24:, the upper section of the unit may be removed for replacing the resistance wires. The resistance wires are connected to the terminals 7 8 and 9 by the screw 27. The insulating strips 20 can be removed when the sections are separated by unscrewing the cup shaped nut 23. In replacing the heating coils, they are preferably placed in forms (not shown) between strips of paraflined paper, which are heated, then chilled, so as to seal the resistance coils in their proper relation. When the upper section is'removed in the manner stated,'the coils may be laced in the-heating unit, and they will ta e their proper positions. The ends of the resistance coils may be connected to the terminals, and the unit may then be reassembled and the paraffined paper burned off, leaving the resistance coils in the proper grooves of the insulating strips.

Since the major portion of the heating unit is made of stampings from sheet metal, it is relatively cheap to manufacture. Any broken insulating strips, such as those shown at 4 or 20, may be easily replaced. The construction is such that the partsmay be as sembled very quickly, and when assembled, will be held rigidly in osition.

The form of unit s own in Figure 1 is circular, but it will be understood that other forms, such as a rectangular form, might be made, witl1out departing in the least from the spirit and the scope of the invention.

I claim:

1. An electrical heating unit comprising a body portion, a plurality of insulating strips carried by said body portion, resistance elements arranged to rest on said strips, a cover portion, insulating strips carried by said cover portion for holding the resistance elements in position, and means for securing said body portion and said cover portion togather.

2. An electrical heating unit comprising a body portion having a plurality of spokelike supporting members, an insulating strip carried by each of the said spoke-like members, resistance elements supported by said insulating strips, a cover portion having spoke-like members arranged to register with the first named spoke-like members, an insulating strip carried by each of the spoke-like members of the cover for holding said resistance elements in position, and means for securing said cover to said body portion.

3. An electrical heating unit comprising a body portion having a plurality of spokelike supporting members, an insulating strip carried by'each of the said spoke-like members, resistance elements supported by said insulating strips, a cover portion having .spokedike members, an insulating strip carried by each of the spoke-like members of the cover for holding said resistance elements in position, and a reflector secured to said body portion underneath said spoke-like members.

4. An electrical heating unit comprising a body portion having a series of-supporting members spaced apart, removable insulating strips carried by said supporting members, resistance elements carried by said insulating strips, and insulating means for holding said resistance elements in position.

5. An electrical heating unit comprising a body portion having a plurality of supporting members spaced apart, each member being provided with a socket, an insulating strip carried in each of said sockets, resist-- ance elements carried by said insulating strips, and insulating means for maintaining said resistance elements in position.

6. An electrical heating unit comprising a metal body portion having supporting membersspaced apart, each of said supporting members being provided with a socket, an insulating strip disposed in each of said sockets, each of said insulating strips having grooves. on its upper surface, resistance elements disposed in the grooves of said strips, a cover portion, insulating means carried by said cover portion for retaining said" resistance elements in said grooves and means for securing said cover portion and said body portion together.

7. An electrical heating unit comprising a metal body portion having supporting members spaced apart, each of said supporting melnb'ersbeing provided with a socket,

, an insulating strip disposed 'in each of said sockets, each of said insulating strips having grooves on its upper surface, resistance elements disposed in the grooves of said strips, a cover portion, insulating means carried by said cover portion for retaining said resist- .ance elements in said grooves, and means including a single screw bolt for securing said cover portion to said body portion.

8. An electrical heating unit comprising a sheet metal body portion having a plurality of integral supporting members, spaced apart, said supporting members having upturned sides to form sockets, an insulating strip disposed in each of said sockets, each of said strips having grooves on its upper edge, resistance elements disposed in said grooves, a nietal cover having integralsupporting members arranged to register with the supporting members of the body portion, insulating strips carried by the supporting members of the cover for holding said resistance elements in position, and means for securing said body portion and said cover together.

9. An electrical heating unit comprising a sheet metal body portion having a plurality of integral supporting members, spaced apart, said supporting members having upturned sides to form sockets, an insulating strip disposed in each of said sockets, each of said strips having grooves on its upper edge, resistance elements disposed in said grooves, a metal cover having integral supporting members arranged to register with the supporting members of the body portion, insulating strips carried by the supporting members of the cover for holding said resistance elements in position, means for securing said body portion and said cover-together, and a reflector secured beneath the supporting members of said body portion.

ROYCE GERALD KLOEFFLER. 

